Salvia x sylvestris ‘Mainacht’
A clump-forming, erect, branched perennial which has oblong-lance-shaped, mid-green leaves. From early to midsummer, indigo-blue flowers are borne in dense, terminal racemes.
Grow in light, moderately fertile, humus-rich, moist but well-drained soil in full sun or light dappled shade. It will reach a height of 70cm and a spread of 35cm.